By rounding to 1 significant figure, estimate the answers to these questions:
a) $72 \times 45$
b) $26 \times 532$
c) $675 \times 351$

Round each number to 1 significant figure.
Multiply the rounded numbers for each question.
a) 70 × 50 = 3500
b) 30 × 500 = 15000
c) 700 × 400 = 280000
The estimated answers are 3500 , 15000 , 280000 ​ .

Explanation

Problem Analysis We are asked to estimate the answers to the given multiplication problems by rounding each number to 1 significant figure. This means we need to round each number to the nearest ten, hundred, or thousand, depending on the number's magnitude, and then perform the multiplication.

Part a Solution a) For 72 × 45 , we round 72 to 70 and 45 to 50. Then we multiply the rounded numbers: 70 × 50 = 3500 .

Part b Solution b) For 26 × 532 , we round 26 to 30 and 532 to 500. Then we multiply the rounded numbers: 30 × 500 = 15000 .

Part c Solution c) For 675 × 351 , we round 675 to 700 and 351 to 400. Then we multiply the rounded numbers: 700 × 400 = 280000 .

Final Answer Therefore, the estimated answers are: a) 3500 b) 15000 c) 280000


Examples
Estimating calculations by rounding to one significant figure is useful in everyday situations, such as quickly calculating the approximate cost of multiple items while shopping. For instance, if you're buying 6 items that cost $4.85 each, rounding to one significant figure gives you 6 items at $5 each, making the estimated total cost $6 \times 5 = $30. This quick estimation helps you ensure you have enough money and provides a rough idea of the total expense without needing exact calculations.

Answered by GinnyAnswer | 2025-07-03

To estimate the products by rounding to 1 significant figure, we find that: a) 72 × 45 estimates to 3500 ,
b) 26 × 532 estimates to 15000 , and c) 675 × 351 estimates to 280000 .
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Answered by Anonymous | 2025-07-04